


Stop fighting, kids!

by losthpfanficwriter (erbkaiser)



Category: Harry Potter - J. K. Rowling
Genre: Abandoned Work - Unfinished and Discontinued, Alternate Universe, F/M, Half-Sibling Incest, Multi
Language: English
Status: Completed
Published: 2017-11-25
Updated: 2017-11-25
Packaged: 2019-11-26 10:42:13
Rating: Mature
Warnings: Underage
Chapters: 1
Words: 3,694
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18179564
Author URL: https://archiveofourown.org/users/erbkaiser/pseuds/losthpfanficwriter
Summary: Harry has a half-sister and they just can't seem to stop fighting. Or can they?Lily died, James lived and remarried.





	Stop fighting, kids!

"Lily, it's him! Take Harry and run!"

James Potter woke up with a shock, his eyes wide as he looked around and found he was in his bed. Emmeline was sleeping next to him but she woke as he stirred.

"Nightmare?" she asked, concern in her voice.

"The usual," James replied. "Go back to sleep, darling. I'll just check on the kids and come back."

She mumbled something in reply as she let Morpheus take her back in her arms.

It had been fourteen long years since his first wife, Lily, had been murdered by Voldemort. Fourteen years ago he had stood there in the door of his home, having just enough time to call to Lily to take Harry and run, before Voldemort had swatted him aside as if he were a fly. By the time he woke Lily was lying dead next to Harry's crib, Harry was crying and hurt, and Voldemort was nowhere to be found.

Sirius Black was first on the scene and together they had wept over Lily, until the next arrival, Hagrid came. Dumbledore had demanded Harry 'for safekeeping', but of course James had had none of that. While Sirius apparated to the Ministry to start the manhunt for Pettigrew – she never even thought of the traitor by his first name any longer, and he had lost the right to use his Marauder name – James had had to face Dumbledore, while Lily was still lying there. The nerve of the man, demanding he'd take Harry and place him with Petunia of all people?

Of course the loss of Lily had been devastating, but the other members of the Order had been there for him, chief and foremost Emmeline Vance. Her fiancé had also been murdered by Voldemort and they found that sharing the pain made it more bearable. After the customary one half year and one day of mourning over Lily, she and James had wed: after all, he needed a wife in his position as a Lord of the Wizengamot, and they had never planned on having Harry being their only child.

A sad smile appeared on his face as he silently got up from the bed to check on the kids. His and Emmeline's daughter, Rose, was fourteen now and would be starting her third year at Hogwarts, while Harry was just recently turned sixteen and would be starting his fifth year.

Silently he opened the door to Rose's bedroom. The bed was empty, causing his heart to jump in his throat. Abandoning his caution he rushed to the next door, Harry's room, and threw the door open.

"D– Dad? What is it?" Harry looked up from his pillow, startled.

"Rose! She's not –"

"I'm here, daddy. What time is it?" a drowsy voice came from the bed. James looked closer and recognised his daughter's brown locks on the pillow.

"Rose Dorea Potter, what are you doing in your brother's bed?" James demanded, his adrenaline still high from the nightmare.

"Baby Rosy had a nightmare and wanted to sleep with her big brother," Harry said, smirking.

"Don't call me a baby, you jerk!" Rose exploded, proving once again that Potter women had a temper.

"Kids, stop fighting. Rose, I was worried, you were not in your bed... Harry, do you mind letting her stay with you for tonight?"

His son shrugged in that irritating teen-aged way. "It's okay, dad. The baby can stay here tonight."

"Don't call me baby or I'll –"

"Thanks," James interrupted his daughter. "Sleep well, kids. Don't fight." Smiling, he stepped out and closed the door. It was still the middle of the night, he might as well see if Emmeline was up for some cuddling... otherwise he'd just get some more sleep.

–-

"That was close," Harry whispered to his sister after they felt sure James had left.

"No kidding," Rose mumbled. Then she punched him on the arm, hard.

"Ouch! Hey, what was that for?"

"Don't call me baby," Rose grumbled.

"Had to make it convincing, didn't I? Now, where were we?" Harry grinned as he lifted the covers up. If their father had checked she would have been horrified to find that neither teen was wearing a stitch of clothing and worse, that there was some suspicious moisture on his daughter's nether region.

"You were gonna try to put it in again," Rose reminded him, then she bit her lower lip. "Harry... are you sure it won't hurt?"

"It'll be fine, Rosey. We just have to get you wet, then it'll go right in... just like with the others," Harry tried to reassure her.

"Can you... lick me some more first?" she asked, unsure.

"I'd love to! You taste great... baby sis," Harry said, smirking as he slid down to get his head between her legs. Rose didn't even have time to retort to the 'baby' remark before she had to resort to biting her knuckle as Harry's skilled tongue started driving her mad again.

That was after all how this started. She had literally walked in on Harry eating out one of his class mates not one week ago. The kids were home for the summer but it wasn't too uncommon for friends to stay over. Harry being sorted into Slytherin had been a surprise but James had dealt with it, and now was all the more proud of his son. Rose herself was a proud Hufflepuff.

Them being in different Houses not to mention being in different years meant their circles didn't quite overlap, but she had gotten used to seeing Tracey or Daphne around at times. Harry and the two girls had bonded almost instantly in their first year together with Theo Nott, and they formed a close group of friends. In fact, for the past two years Harry had been dating Daphne, and Rose had even overheard her father remark to mummy once that they had inquired with the Greengrasses after an official engagement contract, so perhaps there was even more going on.

Whatever the case, everyone was sure the kids weren't up to no good since Tracey Davis was always following Daphne around as a chaperone whenever Daphne and Harry went on a date, and so she would be there as well whenever Daphne was invited over to the Potter home.

But none of that had prepared Rose for the sight that greeted her as she came home unexpectedly, her 'play date' with Cherry Bones, Susan's younger sister, being interrupted as they got into a fight over who was the better seeker, Cedric Diggory or Harry.

Rose had heard strange noises coming from Harry's room and she thought he had been doing something nasty, so she decided to spy on him to rat him out to their mother later. She hadn't quite counted on seeing Harry's girlfriend Daphne lying on his bed, naked as the day she was born, while she was leisurely sliding some kind of pink wand inside her nethers.

Next to her was Tracey, her skirt hiked up and her knickers dangling off one foot, as Rose's brother was kneeling between the blonde's legs and making smacking noises with the occasional hiss of Parseltongue. Judging by how Tracey had her hands in Harry's hair and was moaning and thrashing about as he went to town on her, she loved what he was doing to her.

Rose was even more shocked when after a while Tracey started shouting Harry's name as she shuddered, obviously climaxing, and her shock reached unprecedented levels when she realised Harry had stripped off his own pants and she could see his naked prick for the first time since they had stopped taking baths together when Harry had turned six. Having no reference other than girl's tales she thought her brother was huge.

Daphne leant over and started sucking on his prick until it grew even more massive and was standing up from his body, almost seeming to pulse. Rose's eyes went wide from her spying spot in the doorway as Daphne effortlessly guided Harry's prick inside Tracey's special place. Amazingly it seemed to fit and Tracey was moaning loud enough to wake the dead as Harry started pumping inside her.

Rose had felt that special tingle as she looked on and was mostly unaware that her own hand had slid beneath her clothes and inside her knickers to 'tickle' her own cunny. Not that she was alone in that, for Daphne looked on with great interest while she was pumping her own quim with the pink wand-like object.

For what seemed an eternity Rose looked as her brother made love... no... _fucked_ the girl, until Tracey screamed his name again and obviously came once more.

"Trace... I am close," she heard her brother say a little later.

"Not inside! It's not safe!" Tracey had said, almost panicking, and Rose had seen her brother reluctantly pull out. His prick... no... _cock_ had stood at full mast, slick with Tracey's juices, but that didn't stop Daphne from almost diving on it as she took him in her mouth. Now Harry was the one with his hands in someone's hair, and Rose looked on in awe as Daphne's cheeks expanded to obviously take in his semen. Daphne moved away from Harry's crotch, her cheeks still extended, and leant over Tracey to kiss her. Even from a distance Rose could see Daphne was sharing Harry's cum with her friend.

"Mmm... we're going to _have_ to get you on the Potion, Trace... I want to eat my Harry's cum from your cunt soon," Daphne said after breaking the kiss with Tracey.

"Dammit love, you know what you're doing to me? I want to fuck you so bad," Harry answered to that. Rose's eyes widened again as she saw her brother getting hard once more.

"Not until our wedding night, Harry... you know the contract demands I be a virgin," Daphne said, sounding almost disappointed. "But that doesn't mean we can't have some fun... come, Trace."  
Rose watched on as both girls started licking and kissing her brother's cock once more. Harry seemed to really enjoy it, at least until he looked up, and Rose realised he saw her standing in his doorway, with her hand down her pants, looking on.

Quickly but silently Rose rushed from the doorway, only partially aware her knickers were positively soaked, and had made her way downstairs.

Tracey and Daphne came down a little later, dressed immaculately, and they briefly said her hello's and goodbyes to Rose as she left. Harry followed her down but waited until they were alone before he spoke up.

"Rose? Please don't tell dad."

"Why not? You're in trouble now, Har-Har... they'll ground you until you're seventeen," Rose had said.

"Come on, Rose! Dad and Emmeline wouldn't understand, they think I'm just a little kid still... please?"

"No, I think I'll tell them," Rose had said, sticking out her tongue.

"You horrible little brat!" Harry had rushed over to her and quickly had her pinned under his arm while he rubbed his knuckles on her head.

"Let me go, you dick! Or I'll tell them for sure!"

"Tell us what?" Their father's voice came suddenly, as he stepped through the open door, followed by his wife.

"Harry, let Rose go," Emmeline said, sighing. "I do wish you kids would stop fighting all the time!"

"You're not my mum, you don't tell me what to do," Harry grumbled, but he led go of his half-sister.

"Don't speak to Emmy that way, son," James chided him.

"Harry had girls over!" Rose blurted out.

"Oh really?" Emmeline's eyebrow rose.

"Just Daphne and Tracey, Emm. We were talking about school and stuff," Harry told her.

"Oh, how nice. Daphne is such a well raised young woman," Emmeline said, smiling.

James cut back in now, "Rose, why are you home already? Weren't you spending the night at the Boneses?"

From there the discussion went to their various days. Rose didn't quite know why she hadn't told on Harry then, but the memory kept her hot and bothered so she had to 'pet the kitten' before she could go to sleep.

–-

The next morning at breakfast she found it hard to meet her brother's eyes. If James and Emmeline noticed they didn't say anything, and soon enough both had to leave for work. James was Head Auror, and Emmeline was his second in command, so they usually had long hours.

With a 'Stay good, kids,' Harry and Rose had been left alone.

"I'm going flying in the yard," Harry said after a while.

"Harry? What... why..." Rose trailed off.

"What and why what?"

"Daphne and Tracey... I saw everything, you know."

"Noisy brat," Harry grumbled. "Look, Rosy Baby, don't tell dad or Emm, okay? Daphne and I have a good thing going and I don't want you to ruin it for me."

"Don't call me baby," Rose said, annoyed. "And about that. Aren't you with Daphne? Why then are you... doing _that_... with Tracey?"

Harry rolled his eyes. "Not that it is _any_ of your business, but that was Daphne's idea, actually."

"Oh?"

"It was! Look, brat, you know Daphne and I are betrothed, right?" Harry put his broom back against the back door wall, and walked over to the living room. Rose followed him and they sat down on the couch.

"I guessed as much," she admitted. "So you're really going to marry her?"

"Not yet, but once we both graduate, yeah," Harry confirmed. "Look, it's partially dad's idea. The Greengrasses are a rich and important family, but Samuel, Daphne's dad, only has daughters. So it makes sense for him to make sure his daughter gets a nice match."

"What, you don't care about –"

"Merlin, shut up, brat! Of course I care about Daphne, too. She's been my best friend since first year, well, her and Tracey and Theo."

"Okay, okay. I get it. You're best friends who are going to get married. Yay you. Doesn't explain why you're rutting with Tracey," Rose interjected.

"Real mature word choice there, bratty baby."

"Don't call me baby or I'll –"

"Yeah, yeah. Anyway, part of the contract Samuel and dad signed enforces that Daphne is a virgin until marriage. Don't ask me why, either of them insisted on it, anyway there's ways to check. So yeah... me and Daphne can't do much more than kiss, and a bit of oral." He blushed a bit at that, but that was nothing compared to the full flush that appeared on Rose's face.

"So you and Daphne can't..."

"No, we can't. That's why, Tracey."

"Huh?"

Harry rolled his eyes. "Why am I even telling you this?"

"Because otherwise I'll go straight to dad and mum!"

"Okay, okay. Keep calm, brat. Anyway. Tracey. Yeah, that was Daphne's idea. She and Tracey are, well, sort of lovers."

"What?! You mean she's a dyke?" Rose's eyes went wide.

"Merlin, you're such a dumb little kid. No, idiot, she's not a dyke. They're just sex friends."

"Huh?"

Harry groaned. "Figures I'd get saddled with a dumb Duffer for a sister. You know, sex friends?"

"I'm not dumb, and we're not Duffers! You slimy snake! What's... 'sex friends'?"

"Wow, you really don't know?" Harry smirked. "Okay... either you Duffers don't have the tradition or you're just too much of a baby –" "Hey!" "– to know, but in Slytherin, some girls share beds. Daphne and Tracey, Leona and Fay, etc.. Apparently it's quite common with Pure-bloods, and as long as it's between unmarried women, nobody cares. Anyway, when Daphne and I started dating, she asked me if she was allowed to stay with Tracey. So I told her it was okay, as long as I could watch."

"Pervert," Rose commented. Her cheeks were red enough to make her resemble a tomato, she was sure.

"Hey, I am a perfectly normal, healthy teen," Harry said, laughing. "So, yeah. I guess even a brat like you can imagine what happened when I saw my girlfriend and another hot girl get just about naked and kiss and touch each other."

"I bet," Rose mumbled. She was trying hard not to bring back up the memory of last night.

"Yeah. So, anyway. One thing led to another, and soon enough both girls would suck me off and I'd eat them out. After Daphne and I signed the marriage contract, that soon lead to me screwing Tracey while Daphne looked on, and, well, we see no reason to stop just because we're out of school," Harry said, fidgeting in place.

"What about... when you and Daphne, well, marry?"

"We haven't really talked about it that much, but I suppose we'll make Tracey our mistress. You know she is the half-sister of Roger, the guy who used to be the Ravenclaw Quiditch captain, right?"

"No, I didn't... erm... wasn't he Davies, with an 'e'?"

"Yeah, some kind of silly Pureblood business there. Tracey's mum was a mistress of her father, so she's not officially recognised as part of the family despite having grown up as Roger's sister. Anyway, she's unlikely to get any support from the Davies clan after graduation, and since she's not that interested in other boys and such... I think she'll be very happy as Daphne and my mistress."

"Lucky you. Pervert," Rose grumbled.

"Yeah. So. Erm. Happy now? You're not going to ruin it for me?"

"I... why not? What's in it for me?" Rose bit her lower lip a bit but her look was shrewd.

"Annoying brat," Harry grumbled. "Okay. What do you want to keep silent? Chocolate? Money?"

"As if I can't get that from daddy or mummy," Rose scoffed. "I want the Map."

"Not happening," Harry shut her down. "That is mine. I might let you borrow it next school-year if you're good, but I'm not giving it to you. Try something else."

"Your broom."

"Get real, brat. That's a regulation Firebolt, a broom that can only be handled by the best Quidditch players. You can hardly get off the ground on a broom!"

She stuck out her tongue. "Then... I want the Cloak."

"What? No way! That's mine, it's the Potter _birthright_. Rose, you can't get my heirlooms, even if you _are_ my sister!"

"Half-sister, as you're so fond of reminding me, _big brother_ ," Rose said. Her face was flushed still, but now there was a fire in her eyes.  
"Okay. If you want me to keep still to our parents, you're going to do what I say for a whole day, okay?"

"Dad and Emmeline, not 'our parents'," Harry grumbled. "Okay... Okay. I'll play along. But you'd better swear not to tell them."

"I swear," Rose assured him.

"On your magic," Harry insisted.

"What, you don't trust me?"

"No."

"Slytherin git."

"Dumb Duffer."

"Okay... let's make a deal then. I swear not to tell mum or dad... and you swear to do whatever I say."

"Until they get home?"

"Until midnight."

Harry mused, then nodded. "Okay. Until the stroke of midnight." He spat in his right hand, and held it out. "Come on then, I'll do the bonding."

"Eew," Rose wrinkled her nose, but then spat in her own hand, and clasped his.

Harry took his wand from his back pocket and let the tip rest on their intertwined hands.

"On your magic, do you swear not to tell James and Emmeline Potter what you saw last night?"

"I do."

"Then I swear to do whatever you ask of me, _within reason_ , until the stroke of midnight. Do you accept?"

"Within reason?" she raised an eye-brow.

"I'm not going to let you trick me into giving you my heirlooms using this," Harry explained to her. "Do you accept?"

"I do," Rose said, sticking out her tongue.

"Then let our magic be taken from us should we break this vow. So be it." His wand tip glowed briefly, signing the deal.

"Paranoid git," Rose said, wiping her hand on her skirt.

"I don't trust little babies who try to blackmail me," Harry shot back, wiping his own hand on his trouser leg.

"Fine... but now, you're mine."

"Yeah yeah. So what do you want me to do?"

"Erm... make me a drink."

"By your command," Harry mock-bowed and went to the kitchen.

–-

Rose was enjoying her day. Harry had cleaned up her eternally messy room, had served her drinks and food throughout the day, and now was massaging her shoulders while she relaxed on a sun lounger in their back yard.

"Mmmm... I see now why the girls swoon over you, big brother," she mumbled, enjoying how he removed all tension from her.

"Heh. This is nothing, you should see how I can reduce Daphne to jelly just by rubbing her foot," Harry bragged.

"Show me!" Rose demanded.

"Ugh. Okay, sit up."

She did, and he took her leg. As he started massaging her foot Rose realised why Harry had bragged of his skills, he was _very_ good. So good in fact that she was getting wet... even more so when she thought of what she had seen the previous day.

"Harry?" she said in a small voice.

"Hmm?" He continued his ministrations.

"Harry? Can you... make me feel _good_?"

"What, you don't like this?" Harry's left eyebrow raised in disbelief as he looked up at her.

"I mean... _really_ good?" She reached down, and lifted her skirt up, revealing her yellow knickers to her brother. Her yellow knickers which had turned a little dark in the front as they had turned wet.

"Rose! I'm your brother!" Harry hissed.

"Half-brother, as you always say... and you swore to do whatever I asked..."

"But... this... really?" Harry seemed to waver between outright walking away and giving in.

"I really want this. Please, Harry? For me?"

"But... okay." Hesitating slightly he moved in between her legs and made her scoot forward. He tried not to think of her as Rose, but as just a girl who wanted him...

Slowly he rubbed his hands over her sensitive legs, encouraging her to spread them further. Not that she needed much. His hands reached her soaked knickers and he slid his right hand beneath the fabric.


End file.
